Help with Battery/DC Brushed Motor Calculations

Feb 2020
1
0
Georgia
Hello,

I am working on a project where I need to calculate the power that a specific DC Brushed Motor requires to operate and how much a rechargeable battery should provide to keep the device charged for 48 hours. Currently, the motor is used with 4 double A batteries but I am seeking to replace these with a rechargeable battery. Here is the link to the spec for the motor: Motor (it is the T2-05 PMDC Iron Core Motor. Can anyone help with with the calculations for this?
 
Apr 2017
539
140
that's listed as 3.3V nominal ... and 0.36W .... that's a very nice voltage because it matches LiFePO4 (lithium Iron) rechargeable , this has a very flat discharge of 3.2V ...Not to be confused with li-ion or Li-po which discharge over 4.2 to 3.2 V very awkward ...

LiFePO4 are available in many places . To run for 48Hours you need a battery capacity of 0.36 x 48 = 16 Whrs at least ....

something like this from eBay ...https://www.ebay.co.uk/itm/7000mAh-3-2V-32700-Rechargeable-Battery-Cell-LiFePO4-5C-LII-50-CE-RoHS/114060794897?hash=item1a8e8d9c11:m:m56daimid36977sXR3taO9A


Notice they are listed with their mAh capacity ...it can supply 7000mA for 1hr ... or 70mA for 100 hrs

The Watt hr capacity is 7000mAhrs x 3..2 = 21.6Whrs
 
Last edited:
  • Like
Reactions: neila9876